Reminders crash Outlook

I recently upgraded to Vista and Outlook 2007. I love them both, but
whenever a reminder pops up in Outlook, it crashes the program, giving the
error window "Microsoft Office Outlook has stopped working ... A problem
caused the program to stop working correctly. Please close the program."

I've seen the questions and solutions about cleaning up old reminders and
recurring reminders, and I've done all that. Problem continues. In fact, if
I enter a brand new simple appointment with a reminder, when it's time for
the reminder to pop up, Outlook will crash with the error message described
above.

How can I fix this?

Oh, more info about my setup. I'm using Exchange server through an ASP, and
they also run Blackberry enterprise server for me.
--
Bob

I am running Outlook 2007 and Vista Ultimate 64x. I get the same crash with reminders. They will pop up and if I try to dismiss them, Outlook stops working. I tried disabling Reminders completly which would cause Outlook to crash anyway (when there was a reminder). I turned reminders back on but disabled the warning sound. No change.